There are known many types of infusion devices. Infusions are either applied by gravitational feed or under a certain pressure. Many types of automated systems are known. It is one of the main problems of infusion devices that the introduction of air bubbles into the blood stream is highly dangerous and must be prevented. To this end various devices and techniques have been provided. According to the present invention, a very simple and inexpensive device and technique is provided with which the infusion can be initiated rapidly, and in a safe and simple manner, at the same time preventing the introduction of air bubbles with the infusion, there being provided the conventional means for visually monitoring the rate of the infusion.